Re: Calling all QUERY-GURUS! Help on Collaborative Filtering

[Anna Sobiepanek]

I think it would help if you give the structure of the table and an explanation of what you want done.
As for your sample code: 1. "Cust_ID IN(...)" I would use exists instead of IN
2. you are doing 2 selects of the same table, i don't know it that is allowed, isnt there another table where the Cust_id and booktitle exists?I think the reason why it is crashing is because it is selecting from itself which throws it into a loop.
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http://dev.mysql.com/doc/refman/5.0/en/exists-and-not-exists-subqueries.html

I think this is more for making sure the field exists in another table.
I use it to make sure that all of the FK in a sample database exist in the parent table before i populate the regular database.

SELECT DISTINCT BOOKTITLE b FROM bookstitles
WHERE (BOOKTITLE!='DaVinci Code')
and EXISTS (SELECT * FROM books s WHERE b.CUST_ID = s.CUST_ID);